XGrabKeyboard(3) XLIB FUNCTIONS XGrabKeyboard(3)

NAME

XGrabKeyboard, XUngrabKeyboard - grab the keyboard

SYNTAX

int XGrabKeyboard(Display *display, Window grab_window, Bool
owner_events, int pointer_mode, int keyboard_mode, Time time);

int XUngrabKeyboard(Display *display, Time time);

ARGUMENTS

display Specifies the connection to the X server.

grab_window
Specifies the grab window.

keyboard_mode
Specifies further processing of keyboard events. You can
pass GrabModeSync or GrabModeAsync.

owner_events
Specifies a Boolean value that indicates whether the
keyboard events are to be reported as usual.

pointer_mode
Specifies further processing of pointer events. You can
pass GrabModeSync or GrabModeAsync.

time Specifies the time. You can pass either a timestamp or
CurrentTime.

DESCRIPTION

The XGrabKeyboard function actively grabs control of the keyboard and
generates FocusIn and FocusOut events. Further key events are
reported only to the grabbing client. XGrabKeyboard overrides any
active keyboard grab by this client. If owner_events is False, all
generated key events are reported with respect to grab_window. If
owner_events is True and if a generated key event would normally be
reported to this client, it is reported normally; otherwise, the
event is reported with respect to the grab_window. Both KeyPress and
KeyRelease events are always reported, independent of any event
selection made by the client.

If the keyboard_mode argument is GrabModeAsync, keyboard event
processing continues as usual. If the keyboard is currently frozen
by this client, then processing of keyboard events is resumed. If
the keyboard_mode argument is GrabModeSync, the state of the
keyboard (as seen by client applications) appears to freeze, and the
X server generates no further keyboard events until the grabbing
client issues a releasing XAllowEvents call or until the keyboard
grab is released. Actual keyboard changes are not lost while the
keyboard is frozen; they are simply queued in the server for later
processing.

If pointer_mode is GrabModeAsync, pointer event processing is
unaffected by activation of the grab. If pointer_mode is
GrabModeSync, the state of the pointer (as seen by client
applications) appears to freeze, and the X server generates no
further pointer events until the grabbing client issues a releasing
XAllowEvents call or until the keyboard grab is released. Actual
pointer changes are not lost while the pointer is frozen; they are
simply queued in the server for later processing.

If the keyboard is actively grabbed by some other client,
XGrabKeyboard fails and returns AlreadyGrabbed. If grab_window is
not viewable, it fails and returns GrabNotViewable. If the keyboard
is frozen by an active grab of another client, it fails and returns
GrabFrozen. If the specified time is earlier than the last-keyboard-
grab time or later than the current X server time, it fails and
returns GrabInvalidTime. Otherwise, the last-keyboard-grab time is
set to the specified time (CurrentTime is replaced by the current X
server time).

XGrabKeyboard can generate BadValue and BadWindow errors.

The XUngrabKeyboard function releases the keyboard and any queued
events if this client has it actively grabbed from either
XGrabKeyboard or XGrabKey. XUngrabKeyboard does not release the
keyboard and any queued events if the specified time is earlier than
the last-keyboard-grab time or is later than the current X server
time. It also generates FocusIn and FocusOut events. The X server
automatically performs an UngrabKeyboard request if the event window
for an active keyboard grab becomes not viewable.

DIAGNOSTICS

BadValue Some numeric value falls outside the range of values
accepted by the request. Unless a specific range is
specified for an argument, the full range defined by the
argument's type is accepted. Any argument defined as a set
of alternatives can generate this error.

BadWindow A value for a Window argument does not name a defined
Window.

SEE ALSO

XAllowEvents(3), XGrabButton(3), XGrabKey(3), XGrabPointer(3)
Xlib - C Language X Interface

X Version 11 libX11 1.8.10 XGrabKeyboard(3)